Sam Davis, who is presently a Contributing Editor for Electronic Design, has 18 years of experience in the electronics trade press covering both analog and digital technology—from computer design to power-supply design.
His articles have appeared in PCIM, Real Time Computing, COTS Journal, Computer Design, EDN, and Electronic Design. He is also a recipient of the Jesse Neal Award for trade press editorial excellence.
His engineering experience includes circuit and system design for Litton Systems, Bunker-Ramo, Rocketdyne, and Clevite Corporation. Design tasks included analog circuits, display systems, power supplies, underwater ordnance systems, and test systems. He also served as a program manager for a Litton Systems Navy program. He has one patent for naval ship construction that simplifies electronic system integration.
Davis, who holds a BSEE from Case-Western Reserve University, did graduate work there and at UCLA.
85 results found for Sam Davis, displaying items 1 - 20
March 12, 2009[Engineering Essentials] Rechargeable-Battery Power Management Demands Multiple ICs
Virtually all battery-based powermanagement designs depend on the associated battery, so design starts by picking the specific battery type. The battery may be the non-rechargeable primary type or the rechargeable secondary type. (For more, see “Batteries 101: From Nickel To Lithium And Beyond” at www.electronicdesign.com, ...
February 23, 2009
[Engineering Essentials] Batteries 101: From Nickel To Lithium And Beyond
Virtually all battery-based power-management designs depend on the associated battery, so design starts by picking the specific battery type. The battery may be the non-rechargeable primary type or the rechargeable secondary type. The most widely used rechargeable battery-based systems may employ nickel-cadmium (NiCd), nickel-metal-hydride (NiMH), lithium-ion (Li-ion), or Li-ion polymer, though silver-zinc batteries are now emerging.
February 23, 2009
[Engineering Essentials] Li-Ion Battery Protection ICs
The simplest protection method for battery packs is a fuse that opens if the system draws excessively high current. A more complex protection circuit is found in some battery packs. The battery-protection ICs prevent excessive current, which could lead to high heat. Cells in a lithium-ion (Li-ion) pack may need independent voltage monitoring. The more cells connected in series, the more complex the protection circuit.
January 15, 2009[Technology Report] Ultra-Portables Bank On Power-Frugal Components
Anew breed of components is emerging, significantly reducing power and in turn paving the way for ultra-portable—and ultra-low-power—systems. Needless to say, manufacturers will now look at other products in this vein. Power consumption is the most important design challenge for ultra-portable devices that operate from a limited energy source, such as a lithium-ion battery, according to Ken Marasco, system applications manager at Analog Devices. This...
December 1, 2008
[Technology Report] Switch-Mode ICs Promote Efficient Power Management, Part 1: Switch-Mode Fundamentals
A switch-mode converter circuit uses a controlled power semiconductor switching technique along with an inductor, transformer, or capacitor as an energy-storage element to transfer dc power from its input to its output. In a basic switch-mode converter, a dc-to-pulse-width converter IC accepts a dc input and produces square waves applied to a power semiconductor switch.
December 1, 2008[Technology Report] Low Stored Charge Separates Diode From The Pack
I n an idealized diode, no reverse current flows from cathode to anode when the device is reverse-biased. However, with real-world diodes, large amounts of stored charge can flow from the cathode—back through the anode— before the diode enters its blocking state. That stored charge is QRR, and it causes the reverse recovery current (IRR) that flows as the diode transitions from forward to reverse bias. For example, a...
October 23, 2008[Engineering Essentials] Cooling Techniques Attack MPU Processing Heat
The continuing evolution toward higher-performance microprocessor units (MPUs) has revolutionized the design of computers large and small. This evolution has generally followed Moore’s law—the semiconductor industry doubles transistor density every two years while increasing performance with each new generation. Increased performance has contributed to a rise in microprocessor chip power dissipation and power density. An example of the...
March 13, 2008[Engineering Feature] High Efficiency Challenges Power-Management Design
The semiconductor industry has always forced the power-supply industry to follow its trendsetting lead. For the last decade, that trend has been to cram more transistors into a single package, particularly microprocessors. This led to microprocessors with smaller feature sizes and tighter spacing between internal components. To be operational, smaller feature sizes forced the processors to operate at a lower voltage. This, in turn, required lowervoltage power...
December 3, 2007[Technology Report] Handheld Multimedia ICs Hold The Key To Energy-Efficient Video
Energy efficiency is a key design consideration in a National Semiconductor line of ICs intended for batterypowered phone and video systems. Minimizing power consumption is the common thread in these circuits, which convert digital data into real-world video playback subsystems (see the figure). This involves efficient power sources plus digital techniques that minimize power dissipation using analog, digital,...
November 5, 2007[Technology Report] Next-Generation Multifunction Power ICs Help Shrink Mobile Systems
With mobile equipment manufacturers demanding ever smaller and lighter handheld systems, the trend is to create smaller ICs that offer greater functionality. However, meeting those functionality, size, and weight requirements becomes a more difficult proposition in power-oriented applications. For instance, switching regulators must be very efficient, particularly when multiple switchers are integrated into an IC. Battery- charger circuits must be...
September 27, 2007[Engineering Essentials] Shrewd Thermal Management Helps Defeat The Heat
Despite great strides made by electronic system designers in developing products that perform sophisticated tasks, engineers may encounter performance-limiting factors beyond electronic circuitry - like thermal management. Even if good design practices and reliable components are in place, system reliability can suffer if appropriate temperature controls are not implemented. That's why circuit designers should have a basic understanding of how to manage operating...
August 2, 2007[Technology Report] Patent Law: Who Knows What's Obvious?
According to Jay Sandvos, a partner with Bromberg & Sunstein LLP, a Boston law firm focusing on intellectual property and business litigation, the recent Supreme Court decision makes it much easier for the Patent Office to reject claims as obvious just by adding together pieces of different prior-art references to resemble the claims. In the past, this had to be supported by an analysis. Such analysis would have to demonstrate that someone in the same field...
August 2, 2007[Technology Report] The History Of PMBus Products
PMBus products first hit the market in 2005, and since then, we've seen a steady stream of releases. September 2005: Artesyn Technologies announced its first digital point-of-load (POL) converter. The DPL20C is a non-isolated POL converter in the new family of PMBus-compliant dc-dc converters. The DPL20C is a 20-A output converter that features an extensive set of digital configuration, monitoring, and diagnostic facilities accessible via the PMBus interface. This...
August 2, 2007[Technology Report] The Patents In Question
Power-One's patents cover digital power management and control incorporated in its Z-One system architecture, which controls distributed point-of-load (POL) regulators from a single digital power manager. One of the patents (6,949,916, issued September 27, 2005) is "System and method for controlling a point-of-load regulator." It describes the use of serial bus control (either passively or actively) for a point-of-load (POL) regulator. Here, the...
August 2, 2007[Technology Report] It's Z-One Vs. PMBus In Digital Power Management
Sure, designers of embedded computer systems know digital techniques. But they may not be intimately familiar with the digital management of the power supplies used by their systems. Two methods reign when it comes to implementing digital power management. Yet it's not clear which method will win the favor of system designers—or the favor of the courts. Power-One's proprietary Z-One system was the first method to arrive. Then came the open-standard Power...
Sam Davis, who is presently a Contributing Editor for Electronic Design, has 18 years of experience in the electronics trade press covering both analog and digital technology—from computer design to power-supply design.
His articles have appeared in PCIM, Real Time Computing, COTS Journal, Computer Design, EDN, and Electronic Design. He is also a recipient of the Jesse Neal Award for trade press editorial excellence.
prev. page
[1]
